1. Field of the Invention
The present invention relates to a memory device, and to a system including a memory device electrically connectable to a host circuit.
2. Description of the Related Art
An inkjet printer, which is one example of liquid ejecting apparatus, typically has one or more installed ink receptacles provided as detachable liquid receptacles. Some ink receptacles are furnished with memory devices. The memory device stores information of various kinds, for example, the remaining ink level or the color of the ink in the ink receptacle (see JP 2002-370383 A, JP 2004-299405 A). A control unit provided to the printer communicates with the memory devices of the ink receptacles.
However, in conventional techniques, insufficient consideration is given to the issue of dependability of communication between the control unit provided to the printer and the memory devices provided to the ink receptacles. For example, there is a risk that, for reasons such as faulty contact between the electrical contact portions of the printer and an ink receptacle, communication faults may occur between the control unit provided to the printer and the memory device of the ink receptacle. If operation of the print control unit is continued on with the communication fault unresolved, there is a risk of problems such as errors arising in the memory contents of the memory device.
Meanwhile, some conventional techniques employ error detection codes such as parity bits in order to ensure reliability of the data (see JP 02-68642 A). Typically, an error detection code is used to determine whether actual data contains any errors, and is appended at the end of the actual data. However, a problem with past techniques is that they have not proven sufficiently innovative in terms of making reading and writing of actual data and error detection codes more efficient for particular memory device configurations.
The above issue is not limited to memory devices provided to ink receptacles, but is rather an issue common to all manner of memory devices that electrically connectable to a host circuit.